Problem: Convert $115_{10}$ to base 11. Represent $10$ as $A$, if necessary.
Solution: First we note that $11=11^1<115<11^2=121$. Therefore, we know that $115_{10}$ will be a two digit number in base 11. The digit in the $11^1$ place will be $\text{A}$ because $10\cdot 11^1$ is the largest multiple of $11$ that is less than or equal to $115$, and in base 11, $\text{A}$ is used to represent $10$. The digit in the $11^0$ place will be $5$ because $115-110=5$. The final answer is $\boxed{\text{A5}_{11}}$.